Rotary electric furnace.



A. S. BEMIS.

ROTARY ELECTRIC FURNACE.

APPLICATION FILED JAN. 22, 1912 Patented July 28, 1914.

ATTORNEY UNITED STATES, PATENT OFFICE.

ARTHUR s. BEMIS, OFscLEvELAND, OHIO, ASSIGNOR To NATIONAL cannon O0. O1

CLEVELAND, OHIO, A CORPORATION or NEW JERSEY.

ROTARY ELECTRIC FURNACE.

To all whom it may concern: v Be it known that I, ARTH R S. BEMIS, a resident of Cleveland, in the county of Guyahoga, in the State of Ohio, have invented new and useful Improvements in Rotary Electric Furnaces, of which the, fOllOWIIIg IS a clear and exact description.

This invention relates to rotary electric operate, and at the same time of high eiii-- ciency.

Other advantages will appear in the following description particular reference being had to the drawings in which Figure 1 is a sectional elevation taken on the section line A-A of Fig. 2. Fig. 2 is a section taken on the line B-B of Fig. 1. Fig. 3 is a top view of the furnace shown in Fig. 1 with the hopper removed.

Referring to Fig. 1 the Outer walls of the furnace are indicated at 1. Inside of these outer walls are inner walls 2 extending upward from the base ofthe furnace. The inner walls 2 are joined at the base tO- the outer walls 1. Extending downward from the top of the furnace are other interior walls 3. These are joined to the outer walls 1, by means of the top portion 4. This top portion is shown as being flat although it may be made arched shaped if desired. The innerwalls 3 are supported by stay rods 5 fastened to standards 6 at the outside of the furnace. The walls of the furnace may be made of firebrick though they may be made Of any other heat resisting material. If exceedingly high temperatures are reached in -the furnace, it would be preferable to construct the walls in the vicinity of the heating zone of carbon or carborun um.

On top of the furnace and at one side is a tower 7 for supporting the 'upper electrode.

This tower may be made of materials similar to that of the other furnace walls. Beneath the furnace is a bin 8 composed preferably of firebrick though itmay be 'made,of other material. This bin receives the treated material as will be fully explained later.

The carbon wheel or platform 9 is sup Specification of Letters Patent.

a means for conducting part of the current Patented Jul 28, 1914.

Application filed January 22, .1912. Serial No. 672,618.

ported between the inner walls 3 and 2 by a shaft 10, supported in a lower step bearing 1.1 and an upper bearing 12. The bearing 11 is'supported by a member 11. held by the furnace walls. preferably made of iron. The wheel 9 is preferably fastened to a conducting bracket support 13 which iskeyed or otherwise fastened to the shaft 10. The wheel 14 is shown on the shaft 10 for transmit-ting power to the shaft to rotate it. v

Extending through the tower 7 is a hollow carbon electrode 15 supported by a member 15" which may be raised or lowered by hand screws 16, 17 fastened to'a plate 18 on top of the-tower 7. Bythis arrangement the hollow electrode may be raised and lowered to regulate the current to thereby control the degree of heating. I

have shown only one hollow electrode, butit is obvious that a plurality of these may be used and spaced at various places around the furnace. It is advisable to make the.opening in the lower part of the electrode 15 diverg nt as shown, to prevent the material from c ogging therein.

One terminal 19 of a source of E is connected to the tubular member 15 and the other terminal 19 is connected to the lower bearing support 11. In order to increase the contact surface a gland 2O surrounds the shaft 10 and is supported on the member 11 by metallic standards 21. The gland is packed with graphite and serves as tothe shaft. The remainder passes to the shaft through the bearing 11.' If desired a copper brushmay conduct the current to the shaftlO.

In order to prevent air from reaching the interior of the furnace and causing the carbon wheel 9 and the electrode 15 to be con-- sumed theinner walls 2 have two concentric rings 22, 23 spaced apart so as toleave a channel therebetween. Another concentricring 24 depends from the wheel 9 and extends into the channel between the rings 22 and 23. The'space between?- these two rings is also filled with powdered graphite or other suitable material. By this means the furnace is substantially air tight. However, if desired the furnace can be filled with a gas such as illuminating gas, hydrogen, nitrogen or any other inert gas. A pipe 3'1' having a valve 32 is shown for this purpose.

It may be advisable to use a liquid acket to cool the upper part of the electrode 15 and I have shown a jacket 33 for this purpose.

The operation. of the furnace is as follows:

The granular material is fed intothe furnace through the hopper 27 down through the carbon electrode 15. The charge will initially spread out over the wheel 9 as it emerges from theelectrode in the shape of a 'frustum of a cone, and on account of the current going through a constricted portion of the cone is intensely heated in a very short time. The carbon wheel 9 is slowly revolved by means of the pulley 14, and as it moves fresh material 1s fed down by means of its own weight onto the carbon wheel, which is in turn heated'to the desired point. By this means it is seen that the charge is heated to the desired ,pointand then is removed from the heated region and a fresh supply takes-its place. The charge forms a row or ridge with slanting sides, and the treated part is finally pushed off of the carbon wheel 9 by means of a carbon slab 28 which may be projected from the walls 1 as shown in Fig. 2. This slab may be positioned at any place in the circumference of .the furnace. The treated material falls into The carbon wheel 9 can be formed in onedisk if desirable, though I prefer to form it in sectors as shown in Fig. 2. However, it can be constructed in any manner without departing from the scope of my invention.

The current used in this furnace may be either direct or alternating. The path of the current is from one connection 19 through the carbon electrode 15, and also through the charge therein until the base of the electrode is reached. Here the cur- .rent passes entirely through the pile of material just emerged from the electrode; Then it passes through the carbon wheel 9 to the conducting bracket 13, shaft 10, bearing 11 and member 11 to the lower connection 19., The current also passes to the terminal 19" through gland 20, support 21 and member 11.

The furnace is particularly well suited for the calcination of granular carbon and for the manufacture of graphite, though it may be used for heating any other material to any desired temperatures. Any material that is a conductor of electricity and that will flow through the tube 15 can be treated in this type of furnace.

The temperature reached can be controlled by regulating the current passing through the furnace and also by regulating the speed of rotation of the wheel. If. the wheel is rotated at a very slow rate the tem perature of course will be higher than if it were rotatedat a faster rate. The current sent through the furnace canbe regulated by any means well known in the art, and it can also be regulated by raising or lowering the electrode 15 by means of the hand screws 16, 17 as has been previously explained.

This type of furnace will not become clogged as there is no constricted portion in the heating zone and as the treated material is positively and forcibly'lemoved by the rotating wheel 9. This is an important advantage as it has been found that electric furnaces having a'constricted portion in the electric heating zone are liable to become clogged and the removal. of the treated material below this constricted portion does not always cause the charge above to feed down. I have eliminated this difiiculty in my type of furnace. It is not necessary that the carbon wheel move continuously. It may move intermittently so that the charge is fed downward onto the wheel in a series of steps. It is also not necessary to arrange the wheel in a horizontal position. It could equally as well be inclined.

Having described my invention what I claim is:

1. The method of heating material which consist in feeding it into a space whereby it is formed into a pile, passing an electric current through the peak, and then moving it in a direction substantially at right angles to its perpendicular axis.

2. The method of heating granular material which consists in feeding it intoa space whereby it is formed into a pile, passing an electric current through the peak of the pile, and then moving it substantially at rightangles to the general direction of current flow.

3. In an electric furnace, furnace walls, a lower electrode, said walls and electrode being relatively rotative about a vertical axis, means for feeding the material onto the electrode and means whereby current is transmitted through the material to the electrode as it emerges from said feeding means.

4. In an electric furnace, an electrode rotatable about a vertical axis, means for feeding material thereon, means whereby current is transmitted through the material to said electrode as it emerges from said feeding means, and means for rotating said electrode.

5. In an electric furnace, an electrode rotatable about a vertical axis, a hollow electrode for feeding material thereon, and means for rotating said electrode.

6. In an electric furnace, a conducting member, a hollow electrode for feeding material onto said member and for transmit in'a row thereon, and means for forcing the material off the member.

8. In an electric furnace, outer inclosing walls, a rotating electrode supported on a vertical axis inside the furnace, a hollow electrode extending through the top of the furnace and a hopper for feeding the furnace charge through the hollow electrode onto the rotating electrode, and a member for removing the treated charge from the rotating electrode when it is moved out of the heating zone.

9. In an electric furnace, outer inclosing walls, a horizontal rotating electrode, a hollow electrode extending through the top of the furnace, a hopper for feeding the furnace charge through the hollow electrode onto the rotating electrode, means for re moving the treated charge and means for preventing air from entering the interior of the furnace.

10. In an electric furnace, an inner and an outer furnace wall, said inner wall being separated into upper and lower parts, an

electrode between said parts and means for rotating the electrode'about a vertical axis.

11. In an electric furnace a furnace Wallseparated into upper and lower parts, an electrode therebetween a packing material between the electrode and said parts to prevent the passage of air, and a second furnace wall outside of the inner wall and spaced therefrom. I

12. In an electric furnace, an inner and an outer furnace wall, said inner wall being separated into upper and lower parts, an electrode located between said parts, means for rotating said electrode about a vertical axis, a hollow electrode extending toward said rotatable electrode and means for feed ing the furnace charge therethrough onto the rotatable electrode.

13. In an electric furnace, an outer wall,

ARTHUR S. BEMIS. In presence of- MARY F. LADD, F. D. LAWRENCE. 

